Micro Systems Flashcards
dominant flora in skin
staph epi
dominant flora in nose? what can colonize the anterior nares?
stap epi; staph aureus colonizes
dominant flora in oropharnyx
strep viridans
Dominant flora in a dental plaque
strept mutans
2 Dominant flora of the colon
bacteroides fragilis > E.coli
dominant flora of the vagina? what 2 species can colonize it?
lactobacillus; colonized by E. coli and GBS
what is significant about neonates delivered by C-section in terms of normal flora?
they have no flora at birth, but are rapidly colonized after birth
which 2 bugs cause food poisoning that starts rapidly and ends rapidly?
Staph aureus; Bacillus cereus
2 bugs that cause food poisoning from contaminated seafood
Vibrio parahemolyticus; Vibrio vulnificus
Which bug can cause wound infections from contact with contaminated water/shellfish?
Vibrio vulnificus
Food poisoning from reheated rice?!
Be serious = Bacillus cereus
Food poisoning from meats, mayonnaise, and custard via a pre-formed toxin
Staph aureus
food poisoning from reheated meat dishes
clostridium perfringens
food poisoning from improperly canned foods? what might be a hint?
clostridium botulinum. bulging cans are suspicious
food poisoning from undercooked meat such as hamburgers?
E. coli O157:H7
food poisoning from poultry, meat, or eggs
Salmonella
name 3 bugs that can mimic appendicitis
- yersinia enterocolitica = MCC mesenteric adenitis of peyer’s patches
- non-typhoidal salmonella = mesenteric adenitis of peyer’s patches
- campylobacter jejuni
name 7 bugs that cause bloody diarrhea
(C)an’t (S)top (S)***ting (E)(E)r(Y)throcyt(E)s
- Campylobacter (Puppies, livestock, ingestion of undercooked meat)
- Salmonella (Lactose neg, flagellar motility, has animal reservoir, esp. poultry & eggs)
- Shigella (Lactose neg, very low ID50, produces Shiga toxin; human reservoir only)
- EHEC (can cause HUS; Shiga-like toxin)
- EIEC (invades colonic mucosa)
- Yersinia enterocolitica (daycare outbreaks; pseudoappendicitis)
- Entamoeba histolytica (also “anchovy-paste” exudate on liver abscesses)
comma- or s-shaped organism that grows at 42C and causes bloody diarrhea
Campylobacter “likes the campfire” @ 42C
lactose negative organism with flagellar motility. has an animal reservoir, especially poultry and eggs. causes bloody diarrhea
salmonella
lactose negative. very low infectious dose. humans are the only reservoir for this toxin-producing bad boy. causes bloody diarrhea
shigella
O157:H7 is a strain of this bug. causes bloody diarrhea, HUS, and makes a shiga-like toxin
EHEC
gram negative rod that invades the colonic mucosa and can cause bloody diarrhea
EIEC
day-care outbreaks + pseudoappendicitis + bloody diarrhea
yersinia entercolitica
protozoan that can cause bloody diarrhea
entamoeba histolytica
name 4 bacteria, 2 protozoa, and 2 viruses that cause watery diarrhea = 8 total
- ETEC (Traveler’s; ST & LT toxin)
- Vibrio cholera (comma-shaped; rice-water)
- C. difficile (can also cause bloody diarrhea; Pseudomembranous Colitis)
- C. perfringens (also causes gas gangrene)
Protozoa:
Giardia, Cryptosporidium (immunocompromised)
Viruses:
Rotavirus, Norovirus
name 2 bugs that cause pneumonia in neonates < 4 weeks old
GBS + E.coli
name 5 agents that cause pneumonia in children ages 4 weeks - 18 years, 1 viral + 4 bugs
- RSV
- Mycoplasma
- Chlamydia trachomatis (infants - 3 y/o)
- Chlamydia pneumoniae (school-aged kids)
- S. pneumoniae
(R)unts (M)ay (C)ough (C)hunky (S)putum
name 3 bugs that cause pneumonia in adults ages 18-40 years
mycoplasma
c. pneumoniae
s. pneumoniae
name 5 agents that commonly cause pneumonia in adults 40-65 years old
S. pneumoniae
H. influenzae
Anaerobes
Viruses
Mycoplasma
name 5 agents that commonly cause pneumonia in the elderly > 65 years old
S. pneumoniae
Influenza virus
Anaerobes
H influenzae
Gram negative rods
Name 2 groups of bugs that cause nosocomial pneumonia (HAP)
Enteric gram negative rods
(Klebsiella, Pseudomonas aeruginosa, & E. coli)
Staphylococcus species
Name 5 common (general classes) causes of pneumonia in immunocompromised patients
- Staphylococcus species
- Enteric gram negative rods
- Fungi
- Viruses: CMV (post-transplant), RSV, influenza
- PcP (HIV patients)
which group of bugs commonly causes aspiration pneumonia?
Anaerobes
(Clostridium, Bacterioides, Actinomyces)
also: Fusobacterium & Peptococcus
name 3 bugs that may cause pneumonia in alcoholics or IV drug users
S. pneumoniae
Klebsiella
Staph aureus
Name 3 bugs that commonly cause pneumonia in CF patients
Pseudomonas
Staph aureus
Strep pneumo
Name 3 bugs that commonly cause pneumonia after a viral infection
Staphylococcus
H. flu
Strep pneumo
Most common causes of atypical pneumonia
Mycoplasma (most common)
Viruses (most common in kids)
- influenza viruses, adenoviruses, rhinovirus, RSV
- also may arise after childhood exanthema like rubeola (measles) or varicella (chickenpox)
Others:
- Legionella
- Chlamydia (Ornithosis, via inhalation of dried excreta of infected birds)
- CMV (post-transplant, immunosuppressive Tx)
- Coxiella burnetii (ricketsial; Q fever; farmers & veterinarians)
name 3 bugs that cause meningitis in newborns < 6 months old
GBS
E.coli
Listeria
name 3 bugs + 1 group of viruses that cause meningitis in children ages 6 months-6 years
Strep pneumo
Neisseria meningitidis
H. flu type B
Enteroviruses = polio, echovirus, coxsackie
name 2 bugs and 2 viruses that cause meningitis in patients age 6 years - 60 years. Of these, which is most common in teens?
S. pneumo
N. meningitidis = most common in teens
Enteroviruses = polio, echo, coxsackie
Herpes = HSV 2 for meningitis, HSV 1 for encephalitis
Name 3 bugs that cause meningitis in patients > 60 years old
Strep pneumo
Gram negative rods
Listeria
What two drugs should be started empirically when bacterial meningitis is suspected? What should you add if listeria is suspected?
ceftriaxone + vancomycin (add ampicillin for Listeria)
Name 5 common viral causes of meningitis
Enteroviruses = coxsackie + echo + polio
HSV = HSV-2 meningitis and HSV-1 encephalitis
HIV
West nile virus = arbovirus
VZV
Name 4 common causes of meningitis in HIV infections
Cryptococcus = chronic fungal meningitis
CMV
Toxoplasmosis = protozoal brain abscesses
JC virus = progressive multifocal leukoencephalopathy (PML)
Which bug has greatly decreased incidence of meningitis due to development of a conjugated vaccine 10-15 years ago? Who is most often affected today?
H. flu (Cases are seen in un-immunized children today)
What leads to these findings in CSF?
increased opening pressure
increased PMNs
increased protein
decreased sugar
bacterial meningitis
What leads to these findings in CSF?
increased opening pressure
increased lymphocytes
increased protein
decreased sugar
Fungal or TB Meningitis
What leads to these findings in CSF?
normal or slightly increased opening pressure
increased lymphocytes
normal or slightly increased protein
normal sugar levels
viral (aseptic) meningitis
which bug should you assume as the cause of osteomyelitis if no other info is available?
staph aureus
osteomyelitis in a sexually active person?
N. gonorrhoeae, but more commonly causes septic arthritis
name 2 bugs that cause osteomyelitis in DM or IVDU patients
pseudomonas
serratia
osteomyelitis in sickle cell folks
salmonella (and they ain’t tryna get no pain meds)
2 bugs that cause osteomyeltis in prosthetic replacements
staph aureus + staph epi
what bug can cause vertebral osteomyelitis?
M. TB = pott’s disease
osteolmyelitis in a patient that presents with cat and dog bites or scratches?
pasteurella multocida
in which patient population does osteomyelitis occur most often? what are classic, but non-specific findings?
most occurs in children
elevated CRP and ESR
name 4 common presenting signs/symptoms with cystitis. What is present in the urine?
dysuria + frequency + urgency + suprapubic pain
WBCs (but NO WBC CASTS) in the urine
what is main route of most cases of cystitis?
ascension of microbes from urethra to bladder
Name 3 things that can predispose males to cystitis
infants with congenital defects
vesicoureteral reflux
enlarged prostate in elderly men